Scum removing apparatus for liquids



Feb. 5, 1935. w. B. MARSHALL 1,990,458

SCUM REMOVING APPARATUS FOR LIQUIDS Filed Oct. 12, 1,931 2 Sheets-Sheet 1 x\\\\ & I l v P figs N chum;

gmtoz SCUM REMOVING APPARATUS FOR LIQUIDS Filed Oct. 12, 1931 2 Sheets-Sheet 2 WBJlfars/aall,

Patented Feb. 5, .1935

SCUM REMOVING LIQ APPARATUS FOR UIDS William B. Marshall, Milwaukee, Wis.,

to Chain Belt Company, Milwaukee,

assignor Wia, a

corporation of Wisconsin Application October 12,

1931, Serial No. 568,479

13 Claims. (Cl. 209-208) This invention relates to scum removing apparatus for liquid settling tanks and while primarily intended for use in connection with the 'sediment tanks of sewage disposal systems and similar liquid separation and purification apparatus, it is not limited solely thereto. N

The invention has for one of its objects the provision of means whereby scum and other debris floating on the surface of water or other liquid in such tanks may be more effectively removed therefrom than has been the case in prior devices of a similar character.

' A further object of the invention is to provide means comprising a scum-receiving receptacle or trough associated with a sediment tank, of a sewage disposal apparatus for example, which receptacle is normally inoperative to receive the scum and debris, together with means for intermittently rendering said receptacle receptive to said scum, etc., said last named means preferably being actuated by certain or all of the scrapers or flights of the sludge removing mechanism of the said tank.

A further object of the invention is to provide a scum removing device of the character described which will be simple in construction, oomparatively inexpensive to manufacture and install, and more eflicient in use than those which have been heretofore proposed.

With the above and other objects in view which will appear as the description proceeds, the invention consists in the novel details of construction and combinations of parts more fully hereinafter described, and particularly pointed out in the appended claims.

Referring to the accompanying drawingsforming a part of this specification in which like reference characters designate like parts in all the views:--

Figure 1 is a vertical longitudinal sectional view, partly broken away, through one form of sediment tank now commonly employed in connection with sewage disposal or other similar liquid separation and purification apparatus, illustrating one form of scum removing device constructed in accordance with the present invention associated therewith; v

Figure 2 is an enlarged detail sectional view of the scum removing apparatus when the scum trough cover is closed;

Figure 3 is a view similar to Figure 2 showing the operating mechanism for the scum trough cover having been actuated by one of the conveyor flights to raise the cover;

Figure 4 is a fragmentary transverse sectional elevational view of a portion of the cover actuating mechanism as seen from the left of Figure 2; Figure 5 is a transverse sectional view of a por tion of the scum trough or receptacle and the actuating mechanism, taken approximately on 5 the plane indicated by the line 5-5 of Figure 2, looking in the direction of the arrows; Figure 6 is a fragmentary detail view of aportion of the actuating mechanism, illustrating how the said mechanism is cleared and not tripped or actuated by certain of the conveyor flights, and

\ Figure 7 is a fragmentary longitudinal sectional view illustrating one form of pivotal connection between the actuating scrapers or flights and the conveyor chains.

Referring more particularly to Figure 1, 10 indicates a suitable settling or decanting tank, which in the case of sewage disposal plants of which the illustration is typical, may be in the form of a concrete walled tank having an outlet passage 11 in the end wall 12 through which liquid may pass into the outlet conduit 13. The said tank is also provided adjacent the end opposite to the outlet 11 with a sludge sump 14 into which the sludge or sediment which is deposited upon the bottom surface 15 may be scraped by means of the ransverse scrapers or flights 16 carried by the endless conveyor chains or belts 1'7. The said chains or belts 1'1 pass around the power driven sprockets 18 and the idler sprockets 19 substantially in the manner shown in Figure 1 and the flights 16 carried thereby are adapted to engage the bottom surface 15 as they are moved along the lower run of the conveyor and scrape the sludge or sediment from right to left as viewed in Figure 1 into the sump 14 from which it may be removed in any usual manner.

The upper run of the conveyor chains 1'! in this type of apparatus is usually immediately below the level of the liquid within the tank 10 so that the flights 16 along said upper run usually project a slight distance above the liquid level sub stantially as illustrated. These flights of course are moving from left to right as viewed in Figure 1 and the present invention contemplates not only that the said flights shall movethe scum or dbris floating upon the top of the liquid toward the right as viewed in Figure 1, but also that some or all of the saidfiights maybe employed for actuating suitable mechanism for opening-the closure of the scum trough about to be described.

The said scum trough may comprise the metal or other similar receptacle 20 supported on the end wall 12 with its upper edge substantially at ber 21- which may be hinged to the trough at 22 the tank, which trough preferably extends transversely of the tank for substantially its full width. The said trough is provided with a closure memand which is adapted to normally occupy the closed position illustrated in Figures 1' and 2 under the influence of gravity. The forward wall of the trough 20 is preferably provided with an adjustable plate 23 by means of which the height of the forward edge of the trough may be varied to accommodate the device to varying liquid levels within the tank.

Pivotally connected to the forward edge of the closure member 21 adjacent each end thereof are the links 25, which links are in turn pivotally connected as at 26 to links 27 pivotally mounted as at 28 upon suitable brackets 29 which may be carried by the side walls 30 of the tank 10. A horizontal link 31 is pivotally connected to the links 25 and 27 at the pivot joint 26 and extends some distance to the left as viewed in Figures 1, 2 and 3 where its other end is pivotally connected as at 32 to a swinging arm 33 pivotally mounted as at 34 to a bracket 35 which likewise may be carried by the side wall 30 of the tank. The arm 33 carries at its lower end a roller 36, which roller is adapted to be engaged by certain or all of the flights 16 of the sludge removing conveyor during their travel from left to right whereby the said arms 33 may be moved about their pivots 34 from the position shown in Figure 2 to that shown in Figure 3. Such oscillation of the arms 33 will through the links 31, 27 and 25 cause the closure member 21 to be swung upwardly on its hinge 22 to the open position shown in Figure 3 whereupon the scum or dbris floating on the surface of the liquid, which is being constantly moved toward the trough 20 by the flights 16, may enter the said trough from whichit may flow ofi to any suitable place of disposal.

The conveyor flights 16 normally comprise transverse beams of wood or metal which are suitably attached to the conveyor chains 17 and they are ordinarily provided with metallic wear plates or straps 38 which during the upper run of the conveyor travel rest upon supporting angle irons 39 to prevent sagging of the conveyor. The arms 33, links 31, 2'7 and 25 of which there may be one at each side of the tank 10, are of such a length and so mounted that when the flights 16 are mounted in the usual manner said flights will pass beneath the rollers 36 without engagement therewith as illustrated in Figure 6. In order to employ some or all of the flights as actuators for opening the closure member 21 as above described, such flights as may be desired as actuators are provided with substantially U- shaped straps 40. Substantially below the arms 33 and in alignment with the strap members 40 there are provided suitable cams 41 which are adapted to be engaged by the straps 40 as the flights 16 move along as will be clear from Figures 2, 3 and 4. Those flights which are to be employed as actuators are pivotally connected to the chains or belt 17 by means of suitable brackets 42 rigidly carried by the flights 16, which brackets are pivotally mounted in saddles or ears 43 carried by the chains 17. It thus results that when one of these pivotally mounted flights provided with the depending straps 40 approaches the cams 41, the straps 40 will ride up the inclined surface 45 of the said cams thereby swinging the flight 16 about its pivot from the dotted v v V 1,990,458 or slightly below the level of the liquid within line position shown in Figure 2 to the full line position shown therein and raising the said flight sufliciently out of its normal line of travel to cause it to engage the rollers 36 of the arms 33 whereby the said arms may be swung to the right as viewed in Figure 2 to cause the opening of the scum trough cover. as above explained. Continued movement of the flight 16 toward the right will bring its strap members 40 to the rearward inwardly inclined surface 46 of the cams 41 whereupon the flight will return to its lower position, the rollers 36 will be disengaged thereby and the cover 21 together with its actuating linkage will be returned to the positions shown in Figure 2 by the action of gravity upon the said cover. Any flights or scrapers 16 which are not provided with the straps 40 of course will not be raised by the cams 41 to engage the rollers 36, but will pass beneath the said rollers without engaging them, as illustrated in Figure 6;

By having the scum trough normally closed and only intermittently opening the same for the reception of the scum or other dbris, less water is lost through the scum trough; and since there is not a constant current created by flow into the said trough there is considerably less agitation in the liquid within the tank, which reduction of agitation facilitates the precipitation and 'settling of the liquid materials .carried by the sewage or other liquid.

As above stated the apparatus has been designed primarily for use in connection with sewage disposal plants and has been illustrated in the present drawingsin such connection but it will be readily understood that it is susceptible of other uses and it is not wished to limit its Application to the type of apparatus shown.

It is likewise obvious that those skilled in the art may vary the details of construction and precise arrangement of parts without departing from the spirit of the invention, and therefore it is not wished to be limited to the above disclosure except as may be required by-the claims.

What is claimed is:

1. In scum removing apparatus for settling tanks and the like, a" receptacle for receiving scum and other floating dbris; a movable closure for said receptacle; and means for automatically periodically opening said closure to admit the scum and debris to said receptacle.

2. In scum removing apparatus for settling tanks and the like, a receptacle having an opening at substantially the normal liquid level of the tank for receiving scum and other debris floating on said liquid; a closure for said opening normally closed by gravity to prevent entry of said scum and dbris into said receptacle; and means for automatically periodically raising said closure to admit the scum and debris to said receptacle.

3. In scum removing apparatus for settling tanks and the like which are provided with means for removing the settled solids, a receptacle for receiving scum and other floating dbris; a movable closure for said receptacle; and means operable by said solids-removing means for intermittently opening said closure to admit the scum and debris to said receptacle.

4. In scum removing apparatus for settling tanks and the like which are provided with means for removing the settled solids, a receptacle for receiving scum and other floating dbris; means normally preventing entry of said scum and debris into said receptacle; and means operable by said solids removing means for causing said 1m named means to adinit the scum and dbris to said receptacle.

5. In scum removing apparatus for settling tanks and the like which are provided with traveling scrapers for removing the settled solids, a receptacle for receiving scum and other floating dbris; a movable closure for said receptacle normally preventing entry of said scum and dbris into said receptacle; and means operable by said traveling scrapers for opening said closure to admit the scum and dbris to said receptacle. 6. In scum removing apparatus for settling tanks and the like which are provided with traveling scrapers for removing the settled solids, a receptacle for receiving scum and other floating dbris; a movable closure for said receptacle normally preventing entry of said scum and dbris into said receptacle; and means including an arm operable by said scrapers in ,their travel, and connections between said arm and closure, for opening the closure to admit the scum and dbris to said receptacle.

7. In liquid separation and purification apparatus, a settling tank; means in said tank for removing the settled solids; a receptacle for re ceiving scum and other dbris floating on the surface of the liquid in said tank; and means operable by said solids removing means for rendering said receptacle receptive to said scum and dbris.

8. In liquid separation and purification apparatus, a settling tank; traveling scrapers in said tank for removing the settled solids; a receptacle for receiving scum and other dbris floating on the surface of the liquid in said tank; and means operable by said scrapers during a portion of their travel for intermittently rendering said receptacle receptive to said scum and dbris.

.9. In liquid separation and purification apparatus, a settling tank; traveling scrapers in said tank for removing the settled solids, said scrapers during a portion of their travel moving along the surface of the liquid in said tank, whereby they may impart motion in a substantially horizontal direction to scum and floating dbris on' said surface; a receptacle for receiving the scum and dbris so moved; a closurefgr said receptacle normally preventing entry of said scum and dbris into said receptacle; and means operable by said scrapers as they move along said liquid surface for moving said closure to admit the scum and dbris to said receptacle.

10. In liquid separation and purification apparatus, a settling tank; traveling endless-belt car-' ried scrapers in said tank for removing the setsition to admit said scum and dbris to said receptacle.

11. In liquid separation and purification apparatus, a settling tank; traveling scrapers in said tank for removing the settled solids; a receip tacle for receiving scum and dbris floating on the surface of the ,liquid in said tank; means normally preventing the entry of the scum and dbris into said receptacle; means adjacent the normal path of travel of said scrapers for causing said entry preventing means to admit scum and dbris to saidreceptacle; and means for causing said scrapers to digress from their normal path of travel and actuate said last named means.

12. In liquid separation and purification apparatus, a settling tank; traveling scrapers in said tank for removing the settled solids; a receptacle for receiving scum and dbris floating on the surface of the liquid in said tank; a closure for said receptacle normally preventing the entry of scum and dbris into said receptacle; means adjacent the normal path of travel of said scrapers for moving said-closure to admit the scum and dbris to said receptacle; and means for moving certainof said scrapers out of their normal path of travel to engage and actuate the normal path of travel of said scrapers for moving said closure to admit the scum and dbris to said receptacle; cam engaging means carried by certain oi said scrapers; and cams engageable by said engaging means for diverting said scrapers out of their normal path of travel to cause them to engage and intermittently actuate said moving means.

' 5 WILLIAM B. MARSHALL. 

